benchmark-models
The facts
Its description
Cross-model benchmark for gstack skills. (gstack) Triggers: cross model benchmark; compare claude gpt gemini; benchmark skill across models; which model should I use
The description the agent reads to decide when to use it. Phrases the author says should start it.
When it starts
A person asking to compare how different AI models (Claude, GPT, Gemini) handle the same prompt or gstack skill, or asking which model to use, would make the agent pick this skill.
Things a person might say (the model's guesses)
- “Compare Claude, GPT, and Gemini on this prompt.”
- “Which model should I use for this task?”
- “Run a cross-model benchmark on the /review skill.”
A model's summary of when it is used.
Tools it may use, or may not
allowed-tools: Bash, Read, AskUserQuestion
Tools it may use while it runs without asking you first.
Runs scripts
bin/gstack-skill-start, bin/gstack-learnings-log, bin/gstack-skill-end, bin/gstack-model-benchmark
Scripts the text names. Found by matching words, so treat them as pointers.
Stops for a person
9 lines stop to ask a person (first 5 linked)
Lines that stop and wait for a person before going on. Found by matching words, so treat them as pointers.
What it leads to
Other skills this one hands off to, calls, requires or offers instead, as a model read them.
What leads to it
- gstack hands off to this PROACTIVE all, or user names it gstack, line 234
Other skills that hand off to this one, call it, require it or offer it instead, as a model read them.
Licence
MIT, from LICENSE
The terms its author shares it under, which let it be shown here.
The text
Most marks come from matching words in the file, so treat them as pointers.
<!-- AUTO-GENERATED from SKILL.md.tmpl — do not edit directly --> <!-- Regenerate: bun run gen:skill-docs -->
Raw lines 1 to 18Boilerplate, lines 19 to 142. The same text appears in 26 other files here. Close
Plan Status Footer
Skills that run plan reviews (/plan-*-review, /codex review) include the EXIT PLAN MODE GATE blocking checklist at the end of the skill, which verifies the plan file ends with ## GSTACK REVIEW REPORT before ExitPlanMode is called. Skills that don't run plan reviews (operational skills like /ship, /qa, /review) typically don't operate in plan mode and have no review report to verify; this footer is a no-op for them. Writing the plan file is the one edit allowed in plan mode.
/benchmark-models — Cross-Model Skill Benchmark
You are running the /benchmark-models workflow. Wraps the gstack-model-benchmark binary with an interactive flow that picks a prompt, confirms providers, previews auth, and runs the benchmark.
Different from /benchmark — that skill measures web page performance (Core Web Vitals, load times). This skill measures AI model performance on gstack skills or arbitrary prompts.
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Step 0: Locate the binary
BIN="$HOME/.claude/skills/gstack/bin/gstack-model-benchmark"
[ -x "$BIN" ] || BIN=".claude/skills/gstack/bin/gstack-model-benchmark"
[ -x "$BIN" ] || { echo "ERROR: gstack-model-benchmark not found. Run ./setup in the gstack install dir." >&2; exit 1; }
echo "BIN: $BIN"If not found, stop and tell the user to reinstall gstack.
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Step 1: Choose a prompt
Use AskUserQuestion with the preamble format:
- Re-ground: current project + branch.
- Simplify: "A cross-model benchmark runs the same prompt through 2-3 AI models and shows you how they compare on speed, cost, and output quality. What prompt should we use?"
- RECOMMENDATION: A because benchmarking against a real skill exposes tool-use differences, not just raw generation.
- Options:
- A) Benchmark one of my gstack skills (we'll pick which skill next). Completeness: 10/10.
- B) Use an inline prompt — type it on the next turn. Completeness: 8/10.
- C) Point at a prompt file on disk — specify path on the next turn. Completeness: 8/10.
If A: list top-level gstack skills that have SKILL.md files (from find . -maxdepth 2 -name SKILL.md -not -path './.*'), ask the user to pick one via a second AskUserQuestion. Use the picked SKILL.md path as the prompt file.
If B: ask the user for the inline prompt. It never goes into a shell command: create a prompt file and write the prompt into it verbatim, then use the printed path as the prompt file.
_GT="$(git rev-parse --show-toplevel 2>/dev/null || pwd)/.gstack/tmp"
mkdir -p "$_GT" && chmod 700 "$_GT" || { echo "Not sent: cannot create $_GT for the text file." >&2; exit 1; }
_EX=$(git rev-parse --git-path info/exclude 2>/dev/null) && mkdir -p "$(dirname "$_EX")" && { grep -qxF '/.gstack/tmp/' "$_EX" 2>/dev/null || echo '/.gstack/tmp/' >> "$_EX"; }
PROMPT_FILE=$(mktemp "${_GT:?}/benchmark-prompt.XXXXXX") || { echo "Not sent: mktemp failed in $_GT." >&2; exit 1; }; echo "PROMPT_FILE: $PROMPT_FILE (name: ${PROMPT_FILE##*/})"Write the text into each printed file with your file-write tool (Claude Code's Write tool needs a Read of the empty file first), exactly as it should appear. The text never goes into a shell command, heredoc or quoted argument. If a write fails or is refused, do not send: print the cause, the file path and the command below for sending by hand.
If C: ask for the path. Verify it exists. Use as positional argument.
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Step 2: Choose providers
"$BIN" --prompt "unused, dry-run" --models claude,gpt,gemini,particle,deepseek --dry-runShow the dry-run output. The "Adapter availability" section tells the user which providers will actually run (OK) vs skip (NOT READY — remediation hint included).
If every provider shows NOT READY: stop with a clear message — benchmark can't run without at least one authed provider. Suggest claude login, codex login, gemini login / export GOOGLE_API_KEY, or export OPENROUTER_API_KEY for particle and deepseek (they run in Claude Code, so they also need the claude CLI).
particle and deepseek send the prompt and the working directory's files the model reads to OpenRouter and the model vendor. They load no Claude Code settings files (so a key in a settings.json env block is never sent) and run with the user's environment minus Anthropic credentials. Say so before including them.
If at least one is OK: AskUserQuestion:
- Simplify: "Which models should we include? The dry-run above showed which are authed. Unauthed ones will be skipped cleanly — they won't abort the batch."
- RECOMMENDATION: A (all authed providers) because running as many as possible gives the richest comparison.
- Options:
- A) All authed providers. Completeness: 10/10.
- B) Only Claude. Completeness: 6/10 (no cross-model signal — use /ship's review for solo claude benchmarks instead).
- C) Pick two — specify on next turn. Completeness: 8/10.
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Step 3: Decide on judge
[ -n "$ANTHROPIC_API_KEY" ] || grep -q 'ANTHROPIC' "$HOME/.claude/.credentials.json" 2>/dev/null && echo "JUDGE_AVAILABLE" || echo "JUDGE_UNAVAILABLE"If judge is available, AskUserQuestion:
- Simplify: "The quality judge scores each model's output on a 0-10 scale using Anthropic's Claude as a tiebreaker. Adds about USD 0.05/run. Recommended if you care about output quality, not just latency and cost."
- RECOMMENDATION: A — the whole point is comparing quality, not just speed.
- Options:
- A) Enable judge (adds about USD 0.05). Completeness: 10/10.
- B) Skip judge — speed/cost/tokens only. Completeness: 7/10.
If judge is NOT available, skip this question and omit the --judge flag.
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Step 4: Run the benchmark
Construct the command from Step 1, 2, 3 decisions:
PROMPT_PATH="<prompt-path>"
[ -s "$PROMPT_PATH" ] || { echo "ERROR: $PROMPT_PATH is missing or empty; the benchmark needs a prompt file." >&2; exit 1; }
"$BIN" --models <picked-models> [--judge] --output table -- "$PROMPT_PATH"<prompt-path> is the prompt file from Step 1 (the SKILL.md path, the printed prompt file, or the user's path) and <picked-models> is the comma-separated list from Step 2. Use a path only if it has no ', ", backtick, $ or \; otherwise copy the file into a new Step 1B prompt file and use that.
Stream the output as it arrives. This is slow — each provider runs the prompt fully. Expect 30s-5min depending on prompt complexity and whether --judge is on.
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Step 5: Interpret results
After the table prints, summarize for the user:
- Fastest — provider with lowest latency.
- Cheapest — provider with lowest cost.
- Highest quality (if
--judgeran) — provider with highest score. - Best overall — use judgment. If judge ran: quality-weighted. Otherwise: note the tradeoff the user needs to make.
If any provider hit an error (auth/timeout/rate_limit), call it out with the remediation path.
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Step 6: Offer to save results
AskUserQuestion:
- Simplify: "Save this benchmark as JSON so you can compare future runs against it?"
- RECOMMENDATION: A — skill performance drifts as providers update their models; a saved baseline catches quality regressions.
- Options:
- A) Save to
~/.gstack/benchmarks/<date>-<skill-or-prompt-slug>.json. Completeness: 10/10. - B) Just print, don't save. Completeness: 5/10 (loses trend data).
If A: re-run with --output json and tee to the dated file. Print the path so the user can diff future runs against it.
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Important Rules
- Never run a real benchmark without Step 2's dry-run first. Users need to see auth status before spending API calls.
- Never hardcode model names. Always pass providers from user's Step 2 choice — the binary handles the rest.
- **Never auto-include
--judge.** It adds real cost; user must opt in. - If zero providers are authed, STOP. Don't attempt the benchmark — it produces no useful output.
- Cost is visible. Every run shows per-provider cost in the table. Users should see it before the next run.
From garrytan/gstack at 3f79d81, 2026-11-01. Skills read by DeepSeek V4.1 Flash on 2026-11-04. Summary and techniques by Claude Opus 5.5 on 2026-11-06.